Question

1. which of the following is a closed system? open cup of coffee covered pan with water ocean glass of water

Explanation:

A closed - system allows energy transfer but not mass transfer across its boundary. An open cup of coffee, ocean, and glass of water can exchange mass with the surroundings (evaporation, etc.). A covered pan with water can exchange heat (energy) with the surroundings but mass transfer is restricted as long as the cover is on.

Answer:

covered pan with water